Wednesday, September 7, 2011

Gedmatch is now doing admixture...and chromosome "painting!"!

There is a new and wonderful addition to the website. It is an admixture feature, now in beta version. For example, it will show your percentages, as measured in your DNA, of what compares to populations such as West European, South Asian, etc.  For Americans with varied ancestry, it provides a very interesting glimpse into family history.
Just very recently, a feature called "Genetic Admixture Painting" was added. It is amazing. It gives you a lot of bang for your buck when you test your DNA because it expands your options for using the raw data.

 If you have loaded up your autosomal test results onto, you can just put your kit number into the admixture feature, and there it is. Very interesting, and convenient. Whether it is accurate or not, and bear in mind that it is in its beta version, it certainly gives more of a breakdown into different reference populations than the Population Finder at FTDNA.
Click on the image to see the breakdown.
I look at these admixture breakdown results, wherever I can find them, as informative and fun. As admixture testing improves, results will improve. For now, at least in my opinion, it is to be seen as helpful, but not definitive, in identifying the backgrounds of ancestors.
Comments on the FTDNA forum indicated that the results are comparable to results done on the same samples with other analysts--geneticists, testing companies, scientists. It is important to take the time to look at the reference populations to get an idea of what the percentages mean. The reference population for West Asian might not be what you think of as West Asian, for example.

It is very useful to sign up for the blogs of Dienekes Pontikos, and to look at what he has done with his data. For those of us for whom analyzing numbers is not a natch, it is also useful to check out what professionals and amateurs have to say about all that at some of the forums such as Another useful forum is at FTDNA.
Even more fun is the chromosome breakdown, showing the percentage of admixture on each chromosome! Take chromosome 22, for example. It will show say 22 % East European, 40% West European, 10 % East Asian, and so on. Again, not taking it as perfect science, I do plan to use it with the chromosome browser AND match results to see if I can get a better idea of my ancestry, especially as it compares with that of my matches. The image above is a sample of a chromosmome painting result. The image is provided courtesy of John Olson, of

The Genetic Admixture Painting shows your chromosomes, one by one, brought to life with vibrant colors indicating where on each the segments best match the reference populations. It is gorgeous and fun to look at while pondering one's possible ancestry. The picture below is of admixture.

Image from google images, originally from Dienekes Anthropology blog. The  results for admixture on are based on the data and work of Dienekes Pontikos.

The utilities are free, and well worth looking into for anyone who is looking for more ways to analyze autosomal DNA test results.

Update April 7 2012: DNA forums is now gone.

No comments: